Method of repair to compressor housing and repaired housing

ABSTRACT

A replacement compressor outlet housing includes a compressor outlet housing, having a volute and a radially inwardly extending finger extending from a radially inner end of the volute. The radially inwardly extending finger is welded to an insert. The insert has a bearing support defining a bore. The insert has a web connecting a ledge to the bearing support. The radially inwardly extending finger welded to the ledge.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.17/376,550 filed on Jul. 15, 2021, which is a divisional of U.S. patentapplication Ser. No. 16/284,178 filed on Feb. 25, 2019, now U.S. Pat.No. 11,103,963 granted on Aug. 31, 2021.

BACKGROUND

This application relates to a method of repairing a compressor housingand a repaired compressor housing.

Compressors are utilized in any number of applications. One compressoris provided to supply compressed air to an air cycle machine on anaircraft. In known compressors, a compressor outlet housing has avolute, which provides a changing flow cross-sectional area downstreamof a compressor impeller. The outlet housing further has a bearingsupport, which mounts a bearing on the housing to support a shaftdriving the impeller. An outer ledge provides a support surface for aportion of the impeller. The bearing support is connected to the outerledge through a radially outwardly extending web.

The web is provided as a solid portion and the overall compressorhousing is cast and then machined to a complex shape.

As can be appreciated, the outlet housing sees a number of challenges inoperation and can be damaged. While it has been proposed to replace abearing support with a bearing support insert, damage can occurelsewhere.

SUMMARY

A replacement compressor outlet housing includes a compressor outlethousing, having a volute and a radially inwardly extending fingerextending from a radially inner end of the volute. The radially inwardlyextending finger is welded to an insert. The insert has a bearingsupport defining a bore. The insert has a web connecting a ledge to thebearing support. The radially inwardly extending finger welded to theledge.

These and other features may be best understood from the followingdrawings and specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a known compressor.

FIG. 2A shows a compressor outlet housing.

FIG. 2B is an opposed view of the FIG. 2A compressor outlet housing.

FIG. 3 is a cross-sectional view through the compressor outlet housing.

FIG. 4A shows damage to the compressor outlet housing.

FIG. 4B shows a first step in repairing the compressor outlet housing.

FIG. 5 shows an insert to replace a removed portion of a compressoroutlet housing.

FIG. 6A shows a method step.

FIG. 6B is an enlarged detail of a section Z from FIG. 6A.

FIG. 7A is a flowchart.

FIG. 7B shows a repaired compressor.

DETAILED DESCRIPTION

A compressor 20 includes an impeller 22 driven by a motor 24 through ashaft 34. An inlet 26 supplies air to the impeller 22 and the air iscompressed and delivered to an outlet 28. An outlet housing 30 includesa volute 36 having an innerface 37 defining a flow passage, whichchanges a cross-sectional area between an outlet 23 of the impeller 22and the outlet 28 of the housing. Outlet 28 is connected to an air cyclemachine 29 such as may be utilized in an aircraft application.

As can be seen, the outlet housing 30 includes a bearing support 32,which supports an outer surface of the shaft 34 through bearings 35. Aweb 38 connects the bearing support 32 to a ledge 39. The ledge 39connects the web 38 to the volute 36 through finger 58. As shown, sealteeth 41 on the back of compressor impeller 22 are positioned adjacent asofter material on the compressor outlet housing 30. The seal teeth candig a groove into this portion of the housing to minimize air leakage.

FIG. 2A shows the compressor outlet housing 30. The bearing support 32is connected by the web 38 to the ledge 39. The volute 36 is connectedto the ledge 39 through finger 58.

FIG. 2B is an opposed view of the compressor outlet housing 30 and showsthe inner surface 37. Further, one can see the finger 58 ledge 39, web38, and bearing support 32.

FIG. 3 shows a cross-section through the prior art compressor housing30. As can be seen, bearing support 32 defining a bore 137 to receive abearing is connected to the axially extending ledge 39 through theradially inwardly extending web 38. A radially inwardly extending finger58 actually connects the volute 36 to the ledge 39.

FIG. 4A shows a challenge with the existing compressor outlet housing30. Cracks 100 are shown in the bearing support 32, the web 38 and inthe ledge 39. The compressor outlet housing 30 is an expensive part andis complex to manufacture.

Thus, a way to repair the damaged compressor outlet housing, as shown inFIG. 4A, would be beneficial. As shown in FIG. 4A, a cut 102 is made toremove the damaged area. The cut 102 separates the ledge 39 from theradially inwardly extending finger 58.

An intermediate part 153 is shown in FIG. 4B having the finger 58defining a radially inner surface 222 after the cut at 102 (see FIG.4A). Radially inner surface provides a radial datum point at 222 forsubsequent repair steps. As shown schematically in FIG. 4B, the radiallyinner surface 222 and an axially rear surface 221 of the remainingfinger 58 are machined as at 106 to reach a desired datum. As can beappreciated, the location of the several structures in the compressoroutlet housing must be precisely aligned for the overall compressor 20to operate.

The cut 202 can be made at the point the finger 58 joins the ledge 39 orcan remove a small portion of the finger. With either option, theremaining finger portion is still called a finger for purposes of thisapplication.

An insert 200 is illustrated in FIG. 5 . Insert 200 has a replacementbearing support 202, which roughly matches the bearing support 32 insize, material, etc. A replacement web 204 (also matching the web 38)extends from the bearing support 202 to a replacement ledge 206.Replacement ledge 206 has an axially rear enlarged portion 208 and aforward extending portion 210. A first radius R₁ is defined from acentral axis X of a bore 209 in the bearing support 202 to an outersurface 211 of the forward extending portion 210. A second radius R₂ isdefined from axis X to the outer surface 212 of the rear portion 208. Anaxial distance d₁ is defined from a rear point 220 of the forwardportion 210 to a forward end 231 of the forward portion. A seconddistance d₂ is defined between the forward end 220 of the rear portion208 and a rear surface 207.

As can be appreciated, surface 220 is both the forward end of rearportion 208, and the rear end of forward portion 210.

In one embodiment, R₁ was 4.78 in. (12.14 cm) and R₂ was 4.90 in. (12.45cm). In embodiments, a ratio of R₁ to R₂ is between 0.963 and 0.988.

In one embodiment, d₁ was 0.930 in (2.36 cm) and d₂ was 1.20 in. (3.05cm). In embodiments, a ratio of d₁ to d₂ is between 0.731 and 0.821.

As shown in FIG. 6A, insert 200 is now inserted within the remainingfinger 158 of the intermediate part 153. A weld joint 310 is formed toconnect the two. Electron beam welding is preferably utilized. Theforward end 220 of the rear portion 208 of insert 200 abuts a rearsurface 221 of the finger 158. An outer surface 224 of the forwardportion 210 supports the inner surface 222 of finger 158. As can beappreciated, the location of the axially forward surface 220 of the rearportion 208 and the outer surface 224 of the forward portion 210 arecarefully formed to a desired size and mate with finger 158 to properlyposition the remaining 153 in both radial and axial directions.

As shown in FIG. 6B, the forward surface 220 of the rear portion 208 anda forward surface 221 of the finger 158 provide axial location. Theinner surface 222 of the finger 158 and the outer surface 224 of theforward portion 210 radially position the two portions together. Theweld joint 310 is shown. By having the enlarged portion 208, backupmaterial is provided which will prevent gas entrapment at a backside ofthe weld. At least some percentage of the rear portion 208 is sacrificedto provide the weld joint 310. As such, the repaired part will likelynot have a surface extending to the original R₂.

As shown in FIG. 7A, a flowchart of the method according to thisdisclosure could be said to include a step 500 of removing the damagedhousing from the compressor. Next, a damaged section is removed from thedamaged housing at step 502. Next, the remaining portion of the damagedhousing is machined to a datum at step 504. In step 506, an insert isplaced within the remaining portion. At step 508, the insert is weldedto the remaining portion. At step 510, the repaired compressor housingis replaced in a compressor.

FIG. 7B shows a repaired compressor 520 now having a compressor outlethousing 230, which includes the insert 200 and the remaining part 153.

A method of repairing a compressor outlet housing under this disclosurecould be said to include the steps of: (a) obtaining a damagedcompressor outlet housing having a radially outer volute, a radiallyinwardly extending finger extending to an axially extending ledge, aradially inwardly extending web extending radially inwardly from theledge, a radially inner bearing support defining a bore; (b) identifyinga damaged section within at least one of the bearing support, the web,and the ledge; and (c) removing at least the bearing support and the webleaving a remaining part; (d) inserting an insert having at least areplacement bearing support and a replacement web into the remainingpart after step (c); and (e) welding the insert to the remaining part toprovide a repaired compressor housing.

A method of replacing a compressor outlet housing under this disclosurecould be said to include the steps of (a) removing a first compressoroutlet housing from a compressor having a compressor impeller driven bya motor through a drive shaft, the first compressor outlet housinghaving a first bearing support portion supporting a bearing for thedrive shaft, the first bearing support portion connected through a firstradially outwardly extending web to a first ledge, and a first voluteconnected to the first ledge through a first radially inwardly extendingfinger; and (b) replacing the second compressor outlet housing with asecond compressor outlet housing, the second compressor outlet housinghaving a second volute and a second radially inwardly extending fingerextending from a radially inner end of the second volute, and the secondradially inwardly extending finger being welded to an insert, the inserthaving a second bearing support placed on the drive shaft to support thebearing for said drive shaft, and the insert having a second webconnecting a second ledge to the bearing support, and the radiallyinwardly extending finger welded to the second ledge.

While the removed compressor outlet housing could be removed andrepaired, it is also within the scope of the method that the replacementcompressor outlet housing could have been prepared before the removal ofthe removed compressor outlet housing, and from a different repairedhousing.

A replacement compressor outlet housing under this disclosure could besaid to include a compressor outlet housing, having a volute and aradially inwardly extending finger extending from a radially inner endof said volute. The radially inwardly extending finger is welded to aninsert. The insert has a bearing support defining a bore, and the inserthaving a web connecting a replacement ledge to the bearing support, andthe radially inwardly extending finger welded to the ledge.

Although an embodiment of this invention has been disclosed, a worker ofordinary skill in this art would recognize that certain modificationswould come within the scope of this disclosure. For that reason, thefollowing claims should be studied to determine the true scope andcontent of this disclosure.

1. A replacement compressor outlet housing comprising: a compressoroutlet housing, having a volute and a radially inwardly extending fingerextending from a radially inner end of said volute, and said radiallyinwardly extending finger being welded to an insert; and said inserthaving a bearing support defining a bore, and said insert having a webconnecting a ledge to said bearing support, and said radially inwardlyextending finger welded to said ledge.
 2. The housing as set forth inclaim 1, wherein said finger is machined to ensure a desired datum pointfor a radially inner surface of said finger.
 3. The housing as set forthin claim 2, wherein said ledge has an axially forward portion providinga radial support location for said radially inner surface of saidfinger, and said ledge having an axially rear portion extending radiallyoutwardly for a greater amount to a radially outer surface than does aradially outer surface of said axially forward portion.
 4. The housingas set forth in claim 3, wherein there is an axially forward end of saidaxially rear portion, and said finger abutting the axially forward endto provide axial alignment.
 5. The housing as set forth in claim 4,wherein a portion of said axially rear portion which extends radiallyoutwardly to a greater extent than does said axially forward portion ofsaid replacement ledge section is sacrificed during said welding.
 6. Thehousing as set forth in claim 4, wherein a first distance is definedbetween said axially forward end of said axially rear portion to anaxially forward end of said axially forward portion, and a seconddistance is defined between an axially rear end of said axially rearportion to said axially forward end of said axially rear portion, and aratio of said first distance to said second distance is between 0.731and 0.821.
 7. The housing as set forth in claim 6, wherein the firstdistance is 0.930 in (2.36 cm) and the second distance is 1.20 in (3.05cm).
 8. The housing as set forth in claim 6, wherein a first radius isdefined between a central axis of said bore and the radially outersurface of said axially forward portion, and a second radius is definedbetween the central axis and the radially outer surface of the axiallyrear portion, and a ratio of said first radius to said second radius isbetween 0.963 and 0.988.
 9. The housing as set forth in claim 8, whereinsaid first radius is 4.78 in (12.14 cm) and the second radius is 4.90 in(12.45 cm).
 10. The housing as set forth in claim 1, wherein said ledgehas an axially forward portion providing a radial support location for aradially inner surface of said finger, and said ledge having an axiallyrear portion extending radially outwardly for a greater amount to aradially outer surface than does a radially outer surface of saidaxially forward portion.
 11. The housing as set forth in claim 10,wherein there is an axially forward end of said axially rear portion,and said finger abutting the axially forward end to provide axialalignment.
 12. The housing as set forth in claim 11, wherein a portionof said axially rear portion which extends radially outwardly to agreater extent than does said axially forward portion of saidreplacement ledge section is sacrificed during said welding.
 13. Thehousing as set forth in claim 11, wherein a first distance is definedbetween said axially forward end of said axially rear portion to anaxially forward end of said axially forward portion, and a seconddistance is defined between an axially rear end of said axially rearportion to said axially forward end of said axially rear portion, and aratio of said first distance to said second distance is between 0.731and 0.821.
 14. The housing as set forth in claim 13, wherein the firstdistance is 0.930 in (2.36 cm) and the second distance is 1.20 in (3.05cm).
 15. The housing as set forth in claim 13, wherein a first radius isdefined between a central axis of said bore and the radially outersurface of said axially forward portion, and a second radius is definedbetween the central axis and the radially outer surface of the axiallyrear portion, and a ratio of said first radius to said second radius isbetween 0.963 and 0.988.
 16. The housing as set forth in claim 15,wherein said first radius is 4.78 in (12.14 cm) and the second radius is4.90 in (12.45 cm).
 17. The housing as set forth in claim 11, wherein afirst radius is defined between a central axis of said bore and theradially outer surface of said axially forward portion, and a secondradius is defined between the central axis and the radially outersurface of the axially rear portion, and a ratio of said first radius tosaid second radius is between 0.963 and 0.988.
 18. The housing as setforth in claim 17, wherein said first radius is 4.78 in (12.14 cm) andthe second radius is 4.90 in (12.45 cm).
 19. The housing as set forth inclaim 10, wherein a first distance is defined between said axiallyforward end of said axially rear portion to an axially forward end ofsaid axially forward portion, and a second distance is defined betweenan axially rear end of said axially rear portion to said axially forwardend of said axially rear portion, and a ratio of said first distance tosaid second distance is between 0.731 and 0.821.
 20. The housing as setforth in claim 10, wherein a first radius is defined between a centralaxis of said bore and the radially outer surface of said axially forwardportion, and a second radius is defined between the central axis and theradially outer surface of the axially rear portion, and a ratio of saidfirst radius to said second radius is between 0.963 and 0.988.